Fabrication Of High-Resolution Multi-Ion Image Sensor Using Rubber-Based Negative Resist And Extracellular Ion Imaging In The Hippocampal Slice

Extracellular ions in the brain are important in neurotransmission, and it is necessary to develop a technique to visualize multiple types of ions simultaneously and at high resolution. In this study, we fabricate a 16-μm pitch high-resolution multi-ion image sensor with a K
⁺
-sensitive film patterned on a potential-detecting array sensor using a rubber-based negative resist as a matrix material, and investigate the ion detection characteristics for high-resolution imaging of extracellular ions. The sensor demonstrates good output sensitivity and selectivity for K
⁺
and pH. In a drug stimulation experiment using mouse brain tissue, an increase in potential was observed in K
⁺
-sensitive pixels and a decrease in potential was observed in H
⁺
-sensitive pixels after the administration of the drug NMDA, demonstrating real-time imaging of ion distribution caused by extracellular K
⁺
release and H
⁺
uptake.